Spatial and temporal variation in recovery of hatchery-released red drum (Sciaenops ocellatus) in stock-enhancement of Texas bays and estuaries

Spatial and temporal variation in recovery of hatchery-released red drum (Sciaenops ocellatus) was assessed in nine bays and estuaries along the Texas coast. Sixteen nuclear-encoded microsatellites were used to identify a total of 167 hatchery-released fish among 4325 red drum sampled between the fall of 2006 and the spring of 2009; these were added to 41 recovered hatchery-released fish identified in a prior study of 1332 red drum sampled from Galveston and Aransas bays in the fall of 2005 and spring of 2006. Recovery of hatchery releases across bays and years ranged from 0.28% to 17.65%. Of the 208 recovered hatchery-released fish, 158 were age 0-1,46 were age 1-2, and four fish were age 2-3. The distribution of recovered hatchery-released fish and wild fish differed significantly across sampling periods within and among bays or estuaries. Allelic richness in recovered hatchery-released fish was significantly lower than in both hatchery brood fish and wild fish. In addition, recovered hatchery-released fish were produced by fewer dams, sires, and dam x sire combinations in 2005 and 2006 and by fewer dams and sires in 2007 than would be expected if reproductive success was distributed randomly among brood fish. The spatial distributions of recovered hatchery-released and wild fish deviated from random expectations for samples from the Upper Laguna Madre in the fall of 2006 and spring of 2007 and from West Matagorda Bay in the spring and fall of 2008. Correlation and principal components analysis identified a significant, positive relationship between annual average CPUE and relative annual mortality. No relationship was observed between the number of fish released per hectare and the percentage of recovered hatchery-released fish. Comparisons to other studies of red drum stock enhancement are discussed. (C) 2013 Elsevier B.V. All rights reserved.